d/freebsd-dev
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

On amd64 and i386, tell the compiler to refrain from generating SSE,

Browse Source 
3DNow, MMX and floating point instructions in rtld-elf.

Otherwise, _rtld_bind() (and whatever it calls) could possibly clobber
function arguments that are passed in SSE/3DNow/MMX/FP registers,
usually floating point values.  This can happen, for example, when clang
generates SSE code for memset() or memcpy() calls.

One symptom of this is sshd dying early on amd64 with "PRNG not seeded",
which is ultimately caused by libcrypto.so.6 calling RAND_add() with a
double parameter.  That parameter is passed via %xmm0, which gets wiped
out by an SSE memset() in _rtld_bind().

Reviewed by:	kib, kan
This commit is contained in:
Dimitry Andric 2011-01-04 20:51:28 +00:00
parent 7606ddab28
commit e172464728
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=216977
2 changed files with 2 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
libexec/rtld-elf/amd64/Makefile.inc
View File

@ -1,5 +1,6 @@
# $FreeBSD$
CFLAGS+= -mno-sse -mno-sse2 -mno-sse3 -mno-mmx -mno-3dnow -msoft-float
# Uncomment this to build the dynamic linker as an executable instead
# of a shared library:
#LDSCRIPT= ${.CURDIR}/${MACHINE_CPUARCH}/elf_rtld.x

1
libexec/rtld-elf/i386/Makefile.inc
View File

@ -1,5 +1,6 @@
# $FreeBSD$
CFLAGS+= -mno-sse -mno-sse2 -mno-sse3 -mno-mmx -mno-3dnow -msoft-float
# Uncomment this to build the dynamic linker as an executable instead
# of a shared library:
#LDSCRIPT= ${.CURDIR}/${MACHINE_CPUARCH}/elf_rtld.x